1. Field of the Invention
The present invention relates to a charger that includes a power source control circuit that controls charging of a battery that supplies electric power to an electric power tool, a microcomputer that operates the power source control circuit, and a constant voltage power source circuit that supplies electric power to the microcomputer.
2. Description of the Related Art
A charger related to the above is disclosed in Japanese Laid-Open Patent Publication No. 2005-333708.
The charger disclosed in Japanese Laid-Open Patent Publication No. 2005-333708 includes a charging power source circuit for charging a battery, a power source control circuit that controls charging, and a constant voltage power source circuit that supplies electric power to the power source control circuit. The constant voltage power source circuit is configured such that an output voltage of the constant voltage power source circuit when the charger is disconnected from the battery is lower than that when charging of the battery (normal state) is performed.
The above construction can reduce unnecessary consumption of electric power when the charger is in a standby state.